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Focusing on ancient population genomics research search this blog Wednesday, October 22, Ust’-Ishim belongs to K-M Not long ago I predicted that Ust’-Ishim belonged to a basal form of Y-chromosome haplogroup P see here. As it turns out, the 45, year-old western Siberian genome belongs to K xLT or K-M , which is actually pretty close to my guess. The Ust’-Ishim paper was published today and is behind a paywall here , but the extensive supp info is free. Here’s a map to help visualize the information, featuring Ust’-Ishim as well as Mal’ta boy, another North Eurasian Upper Paleolithic genome published recently. The Ust’-Ishim genome was sequenced from the fossil of a femur bone found on the right bank of the Irtysh River. This area is very close to the Urals, and almost in the middle of the former Mammoth steppe that once stretched across North Eurasia from Iberia to Alaska. Interestingly, M is an ancestral mutation to the markers that define Y-chromosome haplogroups N, Q and R, which possibly dominated North Eurasia since the Upper Paleolithic note that the 24, year-old Mal’ta boy belongs to a basal form of R. Moreover, R1a and R1b are the most frequent haplogroups in Europe today. Thus, it would seem that most European males derive their paternal ancestry from North Eurasian hunter-gatherers whose ancestors spread out across Eurasia from the Middle East over 45, years ago.

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An essential piece of information in this research is the age of the fossils and artifacts. How do scientists determine their ages? Here are more details on a few of the methods used to date objects discussed in “The Great Human Migration” Smithsonian, July DNA remaining in the coprolites indicated their human origin but not their age. For that, the scientists looked to the carbon contained within the ancient dung.

An atom counter for measuring 81Kr and 85Kr in environmental samples. Geochimica et Cosmochimica Acta, 91(0), [4] Jiang, W. et al. (), 39Ar detection at the isotopic abundance level with Atom Trap Trace Analysis, Phys. Rev. Lett. , DOI: /PhysRevLett

A 96, 96 PDF-File For an efficient performance of atom-trap trace analysis, it is important to collimate the particles emitted from an effusive source. Their high velocity limits the interaction time with the cooling laser. Therefore, forces beyond the limits of the scattering force are desirable. The bichromatic force is a promising candidate for this purpose which is demonstrated here on metastable argon The precollimated atoms are deflected in one dimension and the acquired Doppler shift is detected by absorption spectroscopy.

With the experimentally accessible parameters, it was possible to measure a force three times stronger than the scattering force.

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With ocean circulation, climate reconstruction and groundwater management just a few possible applications are named. By measuring the concentration of a radioactive isotope, such as 14C, the age of a water sample can be determined. The dating range of a radioactive isotope is given by its half-life see figure 1. For water that is between 50 and years old, there is a dating gap for which only one radioisotope is available: Dating ranges for radioactive isotopes commonly employed for dating water left defined by the corresponding half-lives right 39Ar is an ideal tracer because it is of cosmogenic origin with negligible anthropogenic contribution and had a constant atmospheric concentration over the last years.

Moreover, as a noble gas it is conservative and not involved in geochemical processes, which e.

Dating of water with Atom Trap Trace Analysis (ATTA) of 39 Ar. In hydrology the age of water, i.e. the time between last equilibrium with atmosphere and the sampling of the water, is of great interest. With ocean circulation, climate reconstruction and groundwater management just a .

Microbial exudate promoted dissolution and transformation of chromium containing minerals Saad, N. Air quality co-benefits and costs under state, regional, or national cooperation to regulate CO2 from existing power plants Saatchi, S. How to Adapt and Mitigate? Investigation of transient friction in rock at low to high slip-rates using a new biaxial machine Saberi, A. Response of plant tundra communities to changes in abiotic and biotic environments: Importance of the temporal dimension Sachson, W.

How much data is really required for rainfall-runoff model calibration? A summary metric view. Effects of soil dissolved organic matter inputs on high-elevation lake metabolism Saeki, T. Implications for Future Predictions, Abstract Title: Boron desorption in subduction forearcs: Systematics and implications for the origin and transport of deeply-sourced fluids Safi, A.

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Costs to Maintain Alternative Septic Systems Many homeowners rely on a septic system for wastewater treatment. If your home has a septic system of any type you are responsible for maintaining it. There are many different types of septic system designs. An AOSS is an on-site sewage treatment system that is not a conventional onsite septic system.

Atom Trap Trace Analysis (ATTA) is a laser-based atom-counting method capable of analyzing environmental isotope tracers 85 Kr, 39 Ar, and 81 Kr, each covering a distinct age range around the respective half-life (Table 1).

Download Now The story goes that charcoal buried in the soil is stable for thousands if not hundreds of thousands of years and increases crop yields. That story is fast unravelling. Biochar is not what it is hyped up to be, and implementing the biochar initiative could be dangerous, basically because saving the climate turns out to be not just about curbing the rise of CO2 in the atmosphere that can be achieved by burying carbon in the soil, it is also about keeping oxygen O2 levels up.

Keeping O2 levels up is what only green plants on land and phytoplankton at sea can do, by splitting water to regenerate O2 while fixing CO2 to feed the rest of the biosphere [1] Living with Oxygen , SiS Furthermore, the acceleration of deforestation spurred by the biofuels boom since appears to coincide with a substantial steepening of the O2 decline. Turning trees into charcoal in a hurry could be the surest way to precipitate an oxygen crisis from which we may never recover.

Burying charcoal to save the climate The International Biochar Initiative IBI , according to its website [4], was formed in July at a side meeting of the World Soil Science Congress at Philadelphia, Pennsylvania, in the United States, by people from academic institutions, commercial ventures, investment banks, non-government organizations and federal agencies around the world, dedicated to research, development, demonstration, deployment, and commercialisation of biochar on a global scale.

Biochar is just charcoal, produced by burning organic matter such as wood, grasses, crop residues and manure, under conditions of low oxygen pyrolysis.

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Leaching in the Platinum Group Metals Industry. Process Mineralogy, Edited by M. Geological Society, London, Special Publications, , 1—14,

Here we report and discuss the first 39Ar groundwater ages obtained by the new analytical method Atom Trap Trace Analysis (ATTA). Groundwater samples from the Upper Rhine Graben aquifers were collected and analysed by established methods for a large range of tracers, including tritium, stable isotopes, noble gases, and 14C. For 39Ar analysis, several tons of water were degassed in the field using a .

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Karst areas consist of chemically soluble rock such as limestone and gypsum. It can be associated with diamonds or gold. The size of the fragments ranges from sand- to cobble-size. The rocks that form from molten lava are classified as extrusive. Terms such as metallic, submetallic are standardized but subjective.

Laboratory for Radio-Krypton Dating. We have developed the Atom Trap Trace Analysis (ATTA) method to analyze 81 Kr and 85 Kr at and below the part-per-trillion (PPT) level [Chen et al., ; Jiang et al., ], and 39 Ar at and below the part-per-quadrillion (PPQ) level [Jiang et al., ].

Pacific Northwest National Laboratory has developed a process for purifying and detecting 39Ar in groundwater using ultra-low-background proportional counters ULBPCs in their shallow underground laboratory. Samples for the 39Ar measurements are collected by extracting the dissolved gases from L of groundwater using a membrane degasification system, and then purified to remove gases other than argon. The resulting measurements yield the 39Ar specific activity of a sample as a percentage of that in modern argon.

This percentage, along with upper and lower bounds corresponding to a selected statistical confidence level, then yields a sample age range. We demonstrate the value of such data in estimating the age distribution of groundwater, using recent theoretical advances that relate the measurement of a radio-decaying tracer concentration to the Laplace transform of the age distribution. Results demonstrate the value of 39Ar data in characterization of the age distribution in cases ranging from very young to carbon old groundwaters.

In addition to solving applied environmental problems at the Hanford Site and elsewhere, Ms. White received her B. She has been a scientist at PNNL for 18 years and has a strong expertise in linking precise measurements of various environmental indicators in historical media to reconstruct past environmental conditions. Brandenberger received her B. Aalseth works in the area of radiation detection for nonproliferation and treaty verification, direct detection of dark matter, neutrino physics, and environmental radiotracers.

He has developed signal processing methods for radiation detection, nuclear physics codes for multi-dimensional spectroscopic analysis, and new designs for ultra-low-background electronics, cryogenic systems, and radiation detectors. Aalseth received his B.